Eire alarm



Oct. 14, 1930. E. YERICKSON ET AL 1,778,630

' FIRE ALARM Filed April 50, 1930 2 Sheets-Sheet 1 INVENTORS. Erick Z'rz'elzson 31% ATTORNEY.

3 Vii/9515515451515! Oct. 14, 1930. c so ET AL FIRE ALARM Filed April 30, 1930 2 Sheets-Sheet 2 mmvrom Erick Z'rzckson BY w ATTORNEY.

Patented Oct. 14, 1930 UNITED STATES PATENT A OFFICE FIRE ALARM Application fl ed April 30,

This invention relates to a fire alarm and has for its primary object to provide, in a manner as hereinafter set forth, a fire alarm in which a spring operated train of gears 6 including an escapement mechanism actuates a striking hammer to sound an alarm, and in which the gear train is normally rendered.

inoperative by a lever which is normally held in engagement with the escapemeut mechanism by means of an ignitible cord, the lever being spring controlled to automatically move out of engagement with the escapement mechanism to permit the operation of the gear train when the cord is severed, as by burning.

A further object of the invention is to provide a fire alarm of thecharacter aforesaid in which the striking hammer, is normally held in engagement with a gong by means of a tension spring, and in which a series of pins are carried by a gear wheel for engagement with the arm of the hammer to intermittently move the latter against the tension of the spring upon the rotation of the gear wheel.

With the foregoing and other objects in view, the invention consists of the novel construction, combination and arrangement of parts as hereinafter more particularly described, and as illustrated in the accompanying drawings .wherein is shown an embodiment of the invention, but it is to be understood that the description and drawings are to be taken as illustrative and that the invention is intended'to be limited only by the scope of the claims hereuntoappended.

In the accompanying drawings in which like numerals are employed to designate like parts throughout the several views Figure 1 is a sectional elevation of a fire alarm in accordance with this invention.

Figure 2 is a vertical transverse section therethrough. V

Figure 3 is a detailed view showing the main gear Wheel from the opposite side to that shown in Figure 1.

Figure 4 is a detailed view showing the cord actuated lever in engagement with the escapement mechanism to prevent the operation of the alarm.

Referring to the drawingsin detail, the

1930. Serial No. 448,639.

numeral 1 indicates a housing which is formed with an open back closed by means of a back plate 2, the backplate 2 being secured to the housing by means. of a plurality of bolts, such as 3, extending therethrough; Centrally thereof the back plate 2 is formed with an upwardly projecting port-ion 4 to the forward face of which is secured a bracket '5 upon which is mounted a gong 6. Disposed within the gong 6, in overlapping relation to the rear edge thereof, is a hammer 7 which is mounted on an arm 8 extending through a slot 9 in the housing 1 and pivotally mounted in spaced relation to its lower end on a suitable bolt 10 extending transversely of the housing 1. Encircling the bolt 10 is a coiled spring 11, one end of which bears against a side face of the arm 8 to normally maintain the hammer 7 in engagement with the gong 6, and the other end of which is fixedly secured to a bolt 12, 9

similar to the bolt 10.

Disposed within the housing 1 is a train of gears similar to that employed in a clock movement. The train of gears includes a main gear wheel 13 rotatably mounted on a shaft 14 extending transversely of the housing and having a ratchet 15 mounted thereon forrotation therewith. Carried by the gear wheel 13 is a pawl 16 which is maintained in engagement with the'teeth of the ratchet 15 by means of a leaf spring 17 mounted on' the wheel 13. Coiled around the shaft 14 is a spiral spring 18, one end of which is fixedly secured to the shaft, and the other end of which is fixedly secured to abolt 19 extending transversely of the housing. The spring 18 is located onthe opposite side of the gear wheel 13 from the pawl 16. The shaft 14 is provided with a suitable key 19 by means of which the shaft may be rotated to tighten the spring 18. 1

Meshing with the teeth of the gear wheel 13 is a pinion 20 which is fixedly mounted on a shaft 21 extending transversely of the housing. Also fixedly mounted on the shaft 21 is a gear 22 which is in mesh with a pinion 23 fixedly mounted on a shaft 24. F ixedly mounted on the shaft 24 is an escapement wheel 25 for engagement with an escapement pawl 26 pivotally mounted on a suitable bolt 27 extending transversely of the housing.

In spaced relation to the bolt 27 is a similar bolt 28 upon which a lever 29 is pivotally mounted intermediate the ends of the latter. Encircling the bolt 28 and having an end portion thereof bearing against the lever 29 is a coiled spring 30 which normally forces the lever 29 out of engagement with the escapement pawl 26. Pivotally connected to one end of the lever 29 is a rigid element, such as a wire 31 which slidably extends through an opening 32 in the housing and to the outer end of which is connected an ignitible cord The cord 33 exerts a force on the lever 29 to force a nose an formed thereon into engagement with the escapement pawl 26 to maintain the latter in steady engagement with the escapement wheel 25. Upon the severing of the cord 33, as by burning, the spring 30 forces the lever 29 out of engagement with the escapement wheel 26 whereby the opera -tion of the gear train by means of the spring 18 is permitted. Upon the rotation of the main gear 13 by means of the spring 18, a series of pins 35 projecting from the gear are successively brought into engagement with the lower end of the arm 8 to swing the latter about the pivot 10 against the tension of the spring 11 whereby the hammer 7 is moved out of engagement with the gong 6. As each of the pins clears the lower end of the arm 8, the spring 11 operates to force the hammer 7 into engagement with the gong 6 to sound the alarm. In order that the hammer 7 may have a sharp, clear contact with the gong 6, a stop 86 is provided which projects from the portion l of the plate 2 into the path of the reciprocating arm 8. The stop 36 is so located that it will be engaged by the arm 8 coincidentally with the engagement of the gong 6 by the hammer 7. 7

It is thought that the many advantages of a fire alarm in accordance with this invention will be readily apparent, and although the preferred embodiment of the invention is as illustrated and described, it is to be understood that changes in the size, shape and arrangement of parts may be resorted to, so long as such changes fall within the scope of the invention as defined in the appended claims.

hat we claim is:

1. A fire alarm comprising, a housing, a spring operated train of gears including an escapement wheel and an escapement pawl disposed within the housing, a pivoted lever adjacent the escapement pawl, an ignitible cord connected with the lever to normally maintain the latter in engagement with the escapement pawl to prevent the operation of the train of gears, a spring engaging the lever to force the same out of engagement with the escapement pawl upon the severing of the cord, a plate projecting upwardly from the housing, a gong carried by the plate, an arm having a hammer mounted on one end thereof and having its other end extending into the housing, a pivotal mounting for the arm intermediate the ends thereof, a spring in engagement with the arm to normally maintain the hammer in engagement with the gong, and a series of pins carried by the train of gears for successive engagement with said arm to move the hammer out of engagement with said gong.

2. A fire alarm comprising, a housing, a spring operated train of gears including an escapement wheel and an escapement pawl disposed within the housing, a pivoted lever adjacent the escapement pawl, an ignitible cord connected with the lever to normally maintain the latter in engagement with the escapement pawl to prevent the operation of the train of gears, a spring engaging the lever to force the same out of engagement with the escapement pawl upon the severing of the cord, a plate projecting upwardly from the housing, a gong carried by the plate, an arm having a hammer mounted on one end thereof and having its other end extending lllLO the housing, a pivotal mounting for the arm intermediate the ends thereof, a spring in engagement with the arm to normally maintain, the hammer in engagement with the gong, a series of pins carried by the train of gears for successive engagement with said arm to move the hammer out of engagement with said gong, said hammer being forced against the gong upon the clearance of the arm by said pins, and a stop projecting from said plate into the path of travel of the arm to provide for a sharp contact of the hammer with the gon 3. A fire alarm comprising, a housing, a spring operated train of gears within the housing, said train of gears including a spring operated main gear wheel, an escapement wheel, and an escapement pawl, a lever pivotally mounted within the housing adjacent the escapement pawl, an ignitible cord connected with the lever to normally maintain the latter in engagement with the escapement pawl to prevent the operation of the train of gears, a spring in engagement with the lever to force the same out of engagement with the escapement pawl upon the severing of said cord, a plate projecting from said housing, a gong carried. by the plate, a hammer for engagement with the gong, an arm having the hammer secured to one end thereof and having its other end projecting into the housing, a pivotal mounting for the arm intermediate the ends thereof, a spring in engagement with the arm to normally force the hammer into engagement with the gong, and a series of pins projecting from said main gear wheel for successive engagement with said arm to move the hammer out of engagement with the gong.

4. A fire alarm comprising, a housing, a spring operated train of gears within the housing, said train of gears including a spring operated main gear wheel, an escapement wheel, and an escapement pawl, a lever pivotally mounted within the housing adjacent the escapement pawl, an ignitible cord connected with the lever to normally maintain the latter in engagement with the escapement pawl to prevent the operation of the train of gears, a spring in'engagement with the lever to force the same out of engagement with the escapement pawl upon the severing of said cord, a plate projecting from said housing, a gong carried by the plate, a hammer for engagement with the gong, an arm having the hammer secured to one end thereof and having its other end projecting into the housing, a pivotal mounting'for the arm in- 2O termediate the ends thereof, a spring in engagement with the arm to normally force the hammer into engagement with the gong, aseries of pins projecting from said main gear wheel for successive engagement with said arm to move the hammer out of engagement with the gong, said hammer being forced against the gong upon the clearance of the arm by said pins, and a stop projecting from said plate into the path of travel of the arm to provide for a sharp contact of the hammer with the gong.

5. A fire alarm comprising, a housing, a spring operated train of gears including an escapement wheel and an escapement pawl,

a pivoted lever adjacent the escapement pawl,

a fusible element connected with the lever to normally maintain the latter in engagement with the escapement pawl to prevent the operation of the train of gears, a spring 49 engaging the lever to force the same out of engagement with the escapement pawl upon the fusing of the fusible element, a plate projecting from the housing, a gong carried by the plate, an arm having a hammer mounted on one end thereof and having its other end extending into the housing, a pivotal mounting for the arm intermediate the ends thereof, a spring in engagement with the arm to normally maintain the hammer in engagement with the gong, and means actuated by the train of gears and operating on said arm for intermittently forcing the hammer out of engagement with the gong.

In testimony whereof, we aflix our signatures hereto.

ERICK ERIGKSON. ANTON. WVARREN. 

